I have a 99 cherokee with a Dana 30 up front and an 8.25 axle in the rear.

I swapped a friend for his 8.25 with an air locker in it for cheap and remembered the gearing was 3.55.

If i remember correctly when i converted my xj to 4wd the front dana 30 axle i pulled from a 98 XJ at the junkyard the tag said it was also a 3.55 gear.

Question: On the ARB site it basically claims for the dana 30 there are two models

3.73 and up - RD100
3.54 and down - RD101

Am i missing something here or am i drawing a blank?!

What is the question exactly?

Well I have 3.55 gears supposedly and they only offer lockers for 3.54 down and 3.73 and up.

that .01 makes it so they dont have one available for my jeep?

Those are based on common Dana configurations. 3.55 and 3.54 are the same for all intensive purposes

If you want the ARB, you will need the 3.54 and down locker. Just be sure you do not plan on gearing down later, because if you are you might as well do it now and save the cash later.

You're fine. 3.55=3.54 and you'll also see 4.10 and 4.11 used interchangably.